This invention relates generally to wire containers and more specifically to a wire container for use in conjunction with a robot-arm-manipulated wire routing tool in the fabrication of wire harnesses.
A completed wire harness typically comprises a multiplicity of wires configured in a desired bundled layout, with the ends of each wire being terminated in a desired manner. For example, each such wire may have a contact affixed to each of its ends, where each contact is to be inserted into a contact holding device, such as a connector plug. In complex arrangements, numerous wires of varying lengths and types can be included in a single wire harness. Furthermore, such wires may require different contact configurations at their respective ends. In these situations, the task of producing wire harnesses becomes a particularly laborious and time consuming task.
Fully automated fabrication is a sought-after goal in the cost effective production of wire harnesses. Such wire harnesses are preferably assembled by means of manipulable tools, sometimes called end-effectors, which are attached to robotic arms and can route wires in predetermined paths, or insert contacts of varying styles into connectors, or both.
An example of a combined contact insertion and wire routing tool for manufacturing wire harnesses is disclosed in U.S. Pat. No. 4,549,347, issued to C. M. Travlos et al on Oct. 29, 1985. Another contact insertion type end-effector tool for use in the robotic assembly of wire harnesses is disclosed in U.S. Pat. No. 4,598,469, issued to M. S. Weixel on July 8, 1986.
Specific steps involved in the automated fabrication of wire harnesses include the unloading of a wire from a wire prep station, loading the wire into a wire container, transporting the wire container to a wire harness formation station, loading the wire container onto the wire routing end-effector tool, routing the wire within the wire container along a predetermined two-dimensional path, and terminating both wire ends.
To date, the approach usually taken to automate the robotic fabrication of a wire harness is the two-arm approach. It consists of using a robot having two arms, the first arm having a wire routing end-effector tool thereon capable of receiving a wire container, placing a wire end into a holder at the harness formation station, routing a specified length of wire along a two-dimensional path, and placing the second wire end into a holder. If the buffered wire end is a contact that requires an insertion into a connector, then a second robot arm which manipulates a contact insertion type end-effector tool will retrieve the contact and proceed to perform a contact insertion while the next wire container is being loaded onto the first robot arm. This action continues on a wire-by-wire basis until all of the wires are routed and properly terminated. In this two-arm robot approach, the wire routing end-effector tool is not responsible for performing contact insertions.
One of the important elements of such an automated wire harness formation station is the wire containing device. It must be constructed to simplify loading of a wire into the container at a wire prep station, be readily transportable from the wire prep station to a wire harness formation station without damaging the wire or its contact terminations, and be tailored to the specific needs of the wire routing end-effector tool at the harness formation station.
Additional requirements affecting the wire container design include the capability, in certain instances, to route and terminate prepared single wires and cables of lengths ranging from 6 inches to 12 feet. Such wires may have American gauge conductor sizes ranging from 16 to 24, and insulation thicknesses of 0.003 to 0.010 inches. The cables to be held and dispensed by the container may consist of prepared coaxial wires, prepared twisted wire cables (twisted pairs being the most common) and shielded cables. The prepared cables may have outside diameters of up to 0.25 inches. Both wire and cables may have tinned ends, ends prepared with MIL-C-39029 crimp contacts or ends prepared with MS 25036 crimp lugs.
Various wire and cable containing and dispensing devices are presently known in the art. Examples of such devices are disclosed in U.S. Pat. Nos. 2,811,322; 2,846,162; 2,987,278; and 4,089,486. In U.S. Pat. No. 4,089,486 for example, the wire is dispensed from an enclosed container via an aperture in the wall of the container. With such an arrangememt, if the wires to be dispensed were to have contacts thereon, as in the applications discussed herein, the contacts would tend to snag on the wall of the container as they exited the closed container. Unfortunately no prior art containers exist which satisfy all of the criteria mentioned herein and a continuing need exists for improvements in such devices.